The present invention relates generally to an improved stable structural wall block, and more particularly to an improved block which is arranged to be stacked vertically for creation of a structure wall such as in a building structure, a fence, or as a retaining wall of straight, curved and/or serpentine configuration. A non-protruding interlock is formed on the block surfaces for inter-engagement between individual vertically stacked blocks with the interlock assisting in stabilizing the structure through enhanced durability and stability. In order to achieve the engagement, flat lips formed on one surface of the block are arranged to engage, retain and/or lock the flat notched base surface of an adjoining block within the zone formed within the lips. In this connection, the lips as formed on the block top surface have integral mutually opposed triangular portions extending inwardly defining opposed apices, while the block lower surface is provided with a notched base of trapezoidal configuration for engagement with the lips. The overall trapezoidal configuration of the block facilitates the creation of either straight walls or walls with more tightly curved, arcuate, and/or sinusoidal configurations.
In the past, various block body designs have been proposed which are of generally rectangular configuration. While certain arcuate configurations may be created from stacked arrays of such blocks, the rectangular block configuration is most readily adapted for creation of relatively straight walls, since the right angular arrangement of its surfaces imposes a practical limitation upon the arcuate configurations possible. While trapezoidal blocks have been in use in the past, trapezoidal configurations with interlocking features provide greater stability along with the ability to create shorter arcs.
Interlocks with sharply protruding features such as tongue and groove arrangements have been proposed, with certain of such arrangements facilitating the erection of stable curved walls with shorter arcs. However certain of these tongue and groove blocks have proven difficult to manufacture and arrange for stacked shipment. Moreover, such blocks typically cannot include a hollow core. Blocks fabricated pursuant to the present invention are capable of manufacture utilizing conventional molds and molding techniques.
While the blocks of the present invention have particular application to the erection of retaining walls, the added stability which the structures provide make the blocks well suited for other applications, including those for certain components of the fence structure in U.S. Pat. No. 5,623,797, entitled xe2x80x9cBLOCK STRUCTURE AND SYSTEM FOR ARRANGING ABOVE-GROUND FENCING, RAILING AND/OR SOUND BARRIERSxe2x80x9d and the structural walls as disclosed in U.S. Pat. No. 6,082,067, entitled xe2x80x9cDRY STACKABLE BLOCK STRUCTURESxe2x80x9d, both of which are assigned to the same assignee as the present invention.
In accordance with the present invention, a block such as a retaining wall block is created which is arranged to be stacked vertically for creation of a retaining wall, with the improved block comprising and incorporating a lower profile interlock which accommodates and facilitates the erection of permanent, rigid, and stable wall structures. Because of their regular configuration, and lack of any extending, protruding, or other anomalous appendages, the block of the present invention can be manufactured and produced utilizing conventional techniques, and may be fabricated within molds that lie flat, or alternatively in molds wherein the blocks are produced on end. Additionally, central hollow cores may be provided in the block, with the cores being desirable for reducing the quantity of material required in production, and also for reducing the gross weight of the product. The former is a cost reduction feature, the latter being a feature which lightens the load for shipping as well as for those persons who move, stack, or otherwise handle the individual blocks from production to ultimate placement and wall assembly.
The wall blocks of the present invention comprise a block body of generally trapezoidal configuration having a central axis extending between parallelly arranged front and rear surfaces. The body is provided with top and bottom surfaces, and with mutually rearwardly converging lateral side walls. As indicated earlier, the trapezoidal configuration of the block increases its utility by making it possible to readily create rigid and durable straight, curved or sinusoidal walls, with the block bodies being interlocked, one to another, when in stacked relationship as may be required for erection of the retaining wall structure. The top surface of the block body has flat front and rear lips formed thereon, with each of the lips having a root portion of trapezoidal configuration with side walls coextensive with the lateral side walls. Each root portion has an integrally attached mutually opposed triangular portion extending inwardly of the block so as to define opposed aligned front and rear apices. These apices are spaced apart along the central axis of the block.
The bottom surface of the block, being trapezoidal, comprises a central base with opposed notches being formed along the front and rear edges, with the front and rear edges of the base being configured so as to be received within and between the opposed front and rear apices. In the erection of curved walls, it is desirable to provide an unbroken surface for exposed portions of the top surfaces. Accordingly, the lateral dimension of the root portion is sufficiently large so as to fully cover and conceal any void created between the leading edge surfaces of the triangular portions of the lips formed on the lower block surface and the notches formed along the base of the superimposed block.
As indicated above, the configuration of the blocks is such that no unusual or outwardly extending or protruding appendage is present, and furthermore the configuration permits and facilitates production of hollow core blocks. The configuration is further designed to facilitate production with the blocks in either flat or on edge. In addition, core pulling techniques such as disclosed in U.S. Pat. No. 5,484,236, entitled xe2x80x9cMETHOD OF FORMING CONCRETE RETAINING WALL BLOCKxe2x80x9d, assigned to the same assignee as the present invention, may be employed in production. The design and arrangement of the block body of the present invention is such that the block can be split to provide textured front and rear surfaces. The configuration further facilitates creation and erection of tightly curved, arcuate and/or sinusoidal retaining walls. While the terms xe2x80x9cfront surfacexe2x80x9d and xe2x80x9crear surfacexe2x80x9d are used throughout, it will be understood that this designation is for purposes of defining the block, without regard to its ultimate disposition in a finished wall structure. In other words, in a finished wall structure, that surface which has been identified as the xe2x80x9crear surfacexe2x80x9d of the block may well be disposed in and along the front of the finished wall.
Therefore, it is a primary object of the present invention to provide an improved retaining wall block which is specifically designed to be stacked vertically for creation of arcuate, curved, and/or sinusoidal configured retaining walls.
It is a further object of the present invention to provide an improved retaining wall block which is designed to be interlocked when stacked adjacent rows or columns, with the interlock being achieved without requiring protruding or outwardly extending appendages or the like on the block surface.
It is yet a further object of the present invention to provide an improved block body of generally trapezoidal configuration and which is provided with interlocking features including upper lips and lower base features which are in engagement, one with the other.
Other and further objects of the present invention will become apparent to those skilled in the art upon a study of the following specification, appended claims, and accompanying drawings.